Not Applicable.
Not Applicable.
1. Field of the Invention
The present invention relates generally to devices used to spool composite coiled tubing. More particularly, the present invention relates to devices that engage composite coiled tubing during the spooling process. Still more particularly, the present invention relates to devices that compressively engage a winding of composite coiled tubing that is being spooled onto a reel. Still more particularly, the present invention relates to devices that oscillate axially to compressively engage consecutive windings of composite coiled tubing that are being spooled onto a reel. Another feature of the present invention relates to methods of spooling composite coiled tubing onto a reel in an even helical layer.
2. Description of the Related Art
Coiled tubing, as currently deployed in the oilfield industry, generally includes small diameter cylindrical tubing made of metal or composites that have a relatively thin cross sectional thickness. Coiled tubing is typically much more flexible and much lighter than conventional drill string. These characteristics of coiled tubing have led to its use in various well operations. Coiled tubing is introduced into the oil or gas well bore through wellhead control equipment to perform various tasks during the exploration, drilling, production, and workover of a well. For example, coiled tubing is routinely utilized to inject gas or other fluids into the well bore, inflate or activate bridges and packers, transport well logging tools downhole, perform remedial cementing and clean-out operations in the well bore, and to deliver drilling tools downhole. The flexible, lightweight nature of coiled tubing makes it particularly useful in deviated well bores.
Conventional coiled tubing handling systems typically include a reel assembly, a tubing injector head, and steel coiled tubing. The reel assembly stores and dispenses tubing and typically includes a cradle for supporting the reel, a rotating reel for storing and retaining the steel coiled tubing, a drive motor to rotate the reel, and a rotary coupling attached to the reel for the injection of gas or liquids into the steel coiled tubing. The tubing injector head pays out and takes up the steel coiled tubing from the borehole.
While prior art coiled tubing handling systems are satisfactory for coiled tubing made of metals such as steel, these systems do not take advantage of beneficial properties inherent in coiled tubing made of composites. One such property is that composite coiled tubing is significantly lighter than steel coiled tubing of similar dimensions. Another useful property is that composites are highly resistant to fatigue failure, which is often a concern with steel coiled tubing. These unique characteristics of composites markedly increase the operational reach of drill string made-up with composite coiled tubing. Thus, composite coiled tubing may allow well completions and workovers to depths previously not easily achieved by other methods. However, these dramatic improvements in drilling operations require handling systems that efficiently and cost-effectively deploy extended lengths of composite coiled tubing.
At the same time, prior art steel coiled tubing handling systems do not adequately address the unique problems inherent with composite coiled tubing. For example, the handling of composite coiled tubing is often complicated by a problem known as xe2x80x9csnaking.xe2x80x9d Snaking occurs when composite coiled tubing is reeled back onto the spool following a trip downhole. Snaking is defined as an undesired non-uniform coiling of the tubing upon the spool assembly so that the organized fashion in which the tubing is preferred to be stored is disrupted and use of the reel storage space is no longer maximized. The tendency of composite coiled tubing to xe2x80x9csnakexe2x80x9d appears to be caused by non-uniformities in the composite material, which in turn may be attributable to variances in the manufacturing process. Snaking on the reel can lead to the tubing becoming tangled during successive deployment operations, thereby increasing process time and cost of service.
Prior art coil tubing handling systems often include a level wind that travels back and forth longitudinally along a reel during spooling. While a level wind may initially align the composite coiled tubing in a smooth wrap, the tension in the spooled composite tubing may be insufficient to maintain the smooth wrap. In such situations, the composite coiled tubing may jump, leading all subsequent wraps to fall into a highly undesirable sinusoidal wrapping pattern.
Prior art steel coiled tubing systems also use stationary mechanical restraints in certain applications. An exemplary mechanical restraint includes a stationary wide compliant roller mounted on a hydraulic piston. The compliant roller presses against the outer layer of steel coiled tubing to prevent the steel coiled tubing from spiraling or unwinding off of the reel. This system is somewhat effective for steel tubing, because steel coiled tubing tends to unwind from the reel to release the considerable potential energy gained when the steel coiled tubing is bent to conform to the contour of the reel.
In contrast, composite coiled tubing does not exhibit as great a tendency to spiral or unwind in a similar fashion because composite coiled tubing is relatively more flexible than steel coiled tubing and thus requires much less energy to bend. Instead, coil tubing tends to kink, or shorten in length when placed on the reel without back-tension. Accordingly, devices that tend to resist only spiraling or unwinding do not adequately address the susceptibility of composite coiled tubing to unpredictable non-uniform movement.
A manual procedure to prevent snaking of composite tubing can be tedious and time-consuming. The take up process must be performed slowly and with much care and supervision. Because a faster take up process saves time and money, there is a need for a handling system that minimizes the effects of snaking. While oil and gas recovery operations could greatly benefit from coil handling systems capable of handling long lengths of coiled tubing made of composite and other similar material, the prior art does not disclose such handling systems.
The present invention features a winding tool that maintains the ordered pattern of windings of composite coiled tubing as the tubing is spooled onto a reel. The winding tool includes a guide, a biasing member, a base, and a driver. Soon after a winding is spooled onto the reel, the biasing member urges the guide against the previous winding so as to prevent undesired movement of the winding. The biasing member is mounted on a base that is propelled by the driver in a oscillatory fashion along the axis of the reel. Optionally, the base may be adapted to ride on a track that provides stability during movement.
In another embodiment, the winding tool features a frame, a guide and a biasing member. The frame includes a lead screw on which the guide is threadedly mounted. The frame also includes a belt arrangement for transferring rotational movement to the lead screw. Rotation of the lead screw propels the guide in oscillatory translational movement. The guide has a plurality of rollers having arcuate surfaces adapted to receive the windings of composite coiled tubing. The biasing member connects with the frame and thereby ultimately urges the guide against the windings.
Thus, the present invention comprises a combination of features and advantages that enable it to overcome various shortcomings of prior art coiled tubing handling devices. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention, and by referring to the accompanying drawings.